Conventional intracranial pressure monitoring involves, to a large extent, surgery with inevitable patient morbidity. Lumbar puncture is the most common medical procedure for the indirect assessment of intracranial pressure. This technique is, however, performed by trained medical personnel and is not especially suitable for serial pressure monitoring. Serial pressure monitoring is normally undertaken by surgically making a bore-hole through the cranium and inserting a tap which is connected to a pressure transducer and recording equipment. The period of time during which such a monitor may remain in place is often severely limited due to the risk of infection and tissue rejection. Because of the associated patient morbidity, risk of infection and the need for professional medical personnel this technique is often not used on patients who might otherwise benefit from pressure monitoring.